<!DOCTYPE html>
<html>
<head>
<style>
span { color: green }
:checked + span { color: red }
input { display: none }
</style>
</head>
<body>
<input type="checkbox" checked="checked" id="foo"><span>There should be no red</span>
<script>
  var foo = document.body.offsetWidth;
  document.getElementById("foo").removeAttribute("type");
</script>
</body>
</html>
